When should an oldschool flash developer use flex?

Question

What are the key differences between Flash and Flex? I have over five years experience with flash and feel very comfortable developing with it and ActionScript3. I find myself more and more curious about Flex and want to know when it is best to use flash or flex. Also, is everything that can be done with MXML, able to be done with AS3? I have a strong understanding of AS3 and OOP and would like to know the diffrences between using AS3 and MXML in Flex.

Answer 1

Flex is great if you quickly want to build a UI, you can mock up a functioning UI in a couple hours. Since it still can be limiting for some custom UI's it's not perfect for everything but if something should "look" more or less like an application and fit in a grid it's super quick to mock up the UI in MXML. Also don't be intimidated of how most Flex apps look (ugly, imo), you can customize everything or easily create your own components.

Putting actionscript in mxml is the same as putting css or javascript in html = really bad. Unfortunately even Adobe has this in multiple examples (probably mostly because it's easier & faster for demostrations).. My personal opinion is that this applies to bindings too, as i don't want to put my data in the UI (mxml).

As an experienced developer I'm sure you don't do any development on the timeline (to clarify the Flash = timeline misconception). Still with Flex you have the UI separated in a framework that handles a lot of the burden with layout so that you can concentrate on the business logic. The rest of the workflow is close to what you probably already have with Flash.

Answer 2

It depends on what kind of applications you are developing now with Flash. I have been a Flash developer (mainly applications) for 7 years. I must honestly say that I was extremely glad when Flex 2 was released because it had the component framework (good components, layout managers, ...) I did not have in Flash. This is IMO the biggest difference between Flash and Flex (or the Flex framework).

MXML is a real blessing, especially when using data binding. In the end, everything is compiled down to ActionScript (check the -keep compiler option), but MXML just saves you so much time.

Answer 3

Flash and Flex provide different ways to produce different things. I am not familiar with Flash, but I would expect that it is dependent on a time-oriented way to produce something, whereas Flex is geared toward more traditional software development. That is, rather than dealing with time and frames in Flash, one is dealing with describing where components should be placed with MXML and how those components work with ActionScript.

One should also be able to write a Flex app with just AS3 and no need MXML.

The main difference between AS3 and MXML in Flex, as far as I know, is that MXML is not intended to be used with application logic, but rather it is intended to be used like HTML/CSS in web pages and puts components and content onto the Flex app. ActionScript is used to program behaviors, components, and other things outside or what MXML does. Thus, if you want to attach an event to a component one would write ActionScript code.

Hope that helps. I am still learning about Flex myself.

Answer 4

Some other differences that come to mind:

Flash allows you to create graphical assets and then work with them immediately. To use those same things in Flex, you need to use Flash to export them to a swf or swc first.

Flex has a layout manager, so applications that have variable window size are waaaay easier to make. For instance, you can take a window and set it to 90% width of the window, and it will change size... not scale mind you, but actually change its width as the window is made larger or smaller. This is not easy outside of the Flex framework.

Data Binding in Flex is a huge timesaver. It essentially creates all of the code you'd need to write in AS3 by simply saying blah="{foo}" The curley braces denote "bind to this".

The Flex Debugger is vastly superior to the Flash one. There is also a Profiler.

Since I started with Flex and not Flash, I'm not sure what kind of IDE is best for Flash dev, but the Eclipse based Flex Builder is quite nice. The code hinting is great. Subclipse integration is great.

Really, Flash and Flex are different beasts. You should know and understand AS3 if you want to use Flex, and since you do, you're in a perfect position to take advantage of Flex's features. Flash is not going anywhere as a tool for making more visually creative pieces, but Flex offers a lot of advantages for application development.

Answer 5

I prefer Flash IDE vs Flex (aka Flex Builder aka Flash Builder for my comment)

In general i would say it depends on the size of the project.

I find it easier to start and finish small projects quickly in Flash.

I would advise Flex for larger projects because it has various debug tools that can save you plenty of time (although i would still just use Flash my self)

But maybe if you really get used to flex, that might not matter.

some Cons of Flex from my experience.

• When working on a team of 4 on a large project, Flex failed to keep the project
• settings from one computer to another. (we shared files using SVN)
• Flex constantly conflicted with SVN for us.
• I felt distant from the art assets.

some Pros of Flex

• being able to follow variable references from one class to another at the click of a button.
• being able to easily see many variables while debugging. w/o needing to trace them.
• and Flash used to not have Custom Class Code hinting, but now with CS5 it does.
• I think you can use the newest features of Flash Player w/o waiting for a new Flash CS#, for example MoleHill (a new 3d api that uses the GPU) has a beta release out right now. and i think the Flex SDK can already use it. hope this helps.

it should be noted that I am a rare case that doesn't prefer flex, most people strongly prefer flex, so you should give it a try at least.

Answer 6

MXML compiles to action script so it's really like a higher level version of that. So, yes, everything that can be done with MXML can be done with actionscript (but not the other way around).

Answer 7

Flash CSx:

1. GUI\Layout: Basic GUI class framework
2. Graphical Content: Great for editing graphical library objects with or without animation
3. Code: Lacks a good code editor

Flex/Flash Builder + Flex Framework:

1. GUI\Layout: Advanced GUI class framework and layout engine (Flex)
2. Graphical Content: Lacks drawing capabilities of Flash, but you can include Flash generated graphics by exporting them for ActionScript into a SWC and importing/referencing the SWC in Flash Builder.
3. Code: Much better code editor than Flash; not sure if it's on par with FlashDevelop
4. Other: Supports MXML, which is basically just another style of laying out content. Instead of writing a bunch of "c = new C()", "c.prop = x", "c.addChild"... you can structure display objects and thier children using XML constructs, and the MXML compiler will convert it all back into the less-readable, but basically the same AS3 code.

These technologies are all related and interoperable. They are natural and predictable extensions of the Flash player and ActionScript techonolgies, but for some reason Adobe developed the Flex/Flex-builder/MXML technologies as a totally separate product, and market it as something totally new and oh-so-amazing. Whatever. So now we have to go back and forth between the two to use all the features, which is LAME. They also have to waste time and resources developing unnecessary, but helpful, packages like the "Flex Component Kit" to reduce the number of steps necessary to get Flash content into Flash Builder.

You have to go back and forth between these applications, because of their mutually exclusive features -- Flash Builder lacks graphics editing, and Flash CSx lacks MXML and a good code editor -- but they're interoperable in the sense that you can use Flex classes in Flash, Flash classes (and their embedded graphics) in Flex, you can use Flash Builder and MXML without Flex, etc.

I think they need a single, truly integrated Flash IDE, so they need to merge Flash Builder into the Flash CSx editor.